Reserve 1/3 cup of flour. Blend the salt and pepper into the rest of it, and dust the veal shanks lightly with the mixture.
Heat the olive oil in a heavy saucepan over high heat. Brown the veal shanks on all sides. Remove from the saucepan.
Add celery, onion, carrots, and leeks and saute until the edges of the onion start to brown.
Add tomato puree and red wine. Bring to a boil, stirring now and then. Reduce by about half. Add the reserved flour and blend into the sauce.
Add enough water (or veal stock, if you have it) to bring the depth of liquid to about an inch and a half. Add marjoram, parsley, thyme, bay and rosemary and return to a boil.
Return the veal shanks to the saucepan, and place the saucepan into a preheated 400-degree oven. Cook for about 90 minutes, or until the meat begins to fall off the bone.
Remove the shanks and keep them warm. Return the saucepan to medium-high heat on top of the stove, and reduce the stock by a third to a half. Skim top of pot to remove foam and fat. Then strain the stock through a fine sieve.
Return stock to a medium simmer and return veal shanks to it, along with the sauce vegetables. Add salt and pepper to taste. Cook long enough for the vegetables to get tender. You may also cook this a little longer to make the sauce thicker, but a thinner sauce is more authentic.